For the equations below, z(t) is the unknown function. Determine whether these equations are (i) linear or nonlinear, (ii) first, second or third order, (iii) homogeneous or nonhomogeneous, (iv) ODEs or PDEs:
z'+5z(1-z)=0
sin(z)z''+2z+7=0
z''+sin(t)z+3z'=0
Can you explain how to check whether these equations meet the requirements or not?